The present invention relates to hobbing tools and, more particularly, to hobbing tools with replaceable cutting inserts.
At present hobs for generating gears below a certain size are generally solid tools made of high speed steel (HSS) or cemented carbide. Replaceable cutting inserts in hobbing tools are uncommon due to the low quality of those tools and their inability to guarantee fine quality of the gear. Indexable inserts are typically used in hobbing tools for roughing, pre-grinding, or pre-shaving operations. Other types of hobbing tools that have provided higher quality gears include inserted-blade cutter assemblies with removable blades, but these blades are made of solid cemented carbide or HSS and are different from each other. They do not provide an indexable insert solution and, therefore, wear on the cutting edges of the blade requires removal and sharpening and recoating or replacement of the blade.
The following documents disclose different hobbing tools CN 103 071 864 A, U.S. Pat. Nos. 4,536,106 A, 3,688,368 A, JP S52 2388 U and JP S63 156617 A.
It is desirable to provide a hobbing tool with replaceable cutting inserts that permits to generate better quality gears with a small module hob. It is further desirable to provide a hobbing tool with replaceable and indexable cutting inserts that permits to generate better quality gears with a small module hob.
According to an aspect of the present invention, a hobbing tool comprises a hob body comprising at least one axially extending slot, at least one cassette removably disposed in the at least one slot, wherein the at least one cassette comprises at least one seating recess having at least a bottom abutment surface and two side abutment surfaces, and at least one cutting insert removably mounted in the at least one seating recess, at least one cutting insert having at least one bottom supporting surface and two side supporting surfaces that abut the bottom abutment surface and the two side abutment surfaces when the at least one cutting insert is received in the at least one seating recess. The hob body comprises a plurality of axially extending slots. The hobbing tool comprises a corresponding plurality of cassettes removably mounted in the plurality of axially extending slots. Each cassette of the plurality of cassettes is identical to every other cassette of the plurality of cassettes.